The Reign of Terror (Doctor Who)

The Doctor, Ian, Barbara and Susan arrive in what they believe to be England. However, it is soon clear that they have travelled back into Earth history yet again, this time to 18th Century France. They have arrived in a wood twelve kilometres from Paris, then venture to a nearby farmhouse, which seems to have seen better days. When they venture inside they find the farmhouse is being used as a staging post in an escape chain for counter-revolutionaries and contains clothes – some of which are put to good use by the travellers - and fake papers, some of which bear the signature of Robespierre, the chief orchestrator of government during the Reign of Terror. Before long they are found by two counter-revolutionaries, D'Argenson and Rouvray, who knock the Doctor unconscious and hold the others at gunpoint. The impasse is ended when a band of revolutionary soldiers surrounds the house and demands their collective surrender. Both D'Argenson and Rouvray are killed during the siege, but only after they have worked out that there must be a traitor in their escape chain. The soldiers now enter the house and capture Ian, Barbara, and Susan, who will be marched to Paris and the guillotine. The parting action of the soldiers is to set fire to the farmhouse – unaware there remains one person inside.
　　The Doctor awakes the next morning suffering from exhaustion and smoke inhalation. He was saved from the blaze by a young boy, who tells him his friends have been taken to the Conciergerie Prison in Paris. He sets off after them and, after a brief period press-ganged into a road mending crew for lack of papers, makes some speed in the twelve-kilometre journey.
　　Things are looking grim for Ian, Barbara and Susan. They are all sentenced to death as traitors without a chance to speak in their own defence, and are all promised the guillotine for their crimes. Back at the Conciergerie, Ian is confined in one cell, while the women are taken to another. Ian's cellmate is an English prisoner named Webster who only lives long enough to tell him there is another English spy, James Stirling, highly placed in the French Government who is now being recalled to England. It was Webster's job to find him and he only knows that Stirling can be found through Jules Renan at the sign of "Le Chien Gris". Once Webster is dead a government official named Lemaitre arrives and probes any conversation between Ian and the dead man. Lemaitre also crosses Ian's name off the execution list.
　　Susan and Barbara are less fortunate. Confined to the filthiest cell in the jail when Barbara refused the advances of their drunken jailer, they are soon taken on a tumbrel to the guillotine. Luckily for them their transport is hijacked by two men, Jules and Jean, who spirit them back to their safe house. Susan is, however, somewhat ill from her exposure to damp conditions. They are told they will be given food and a place to rest, and then they will be smuggled out of France in the escape chain, but Barbara is nervous about leaving France without the Doctor and Ian. Jules and Jean reassure her they will try to reunite the four travellers, and they all exchange tales of the fate of D'Argenson and Rouvray, whom it seems were part of the same escape chain. Another counter-revolutionary, Leon Colbert, arrives and joins their company, immediately striking up a romantic liaison with Barbara.
　　The Doctor has finally reached Paris and exchanges his clothes and Roman ring for the costume of a Regional Officer of the Provinces plus some parchment and writing materials. In this guise he heads for the Conciergerie, but by the time he gets there all three of his companions have gone. Ian has succe